RHEL 4 / 5 : ruby (RHSA-2012:0070)

High Nessus Plugin ID 57747


The remote Red Hat host is missing one or more security updates.


Updated ruby packages that fix two security issues are now available for Red Hat Enterprise Linux 4 and 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to do system management tasks.

A denial of service flaw was found in the implementation of associative arrays (hashes) in Ruby. An attacker able to supply a large number of inputs to a Ruby application (such as HTTP POST request parameters sent to a web application) that are used as keys when inserting data into an array could trigger multiple hash function collisions, making array operations take an excessive amount of CPU time. To mitigate this issue, randomization has been added to the hash function to reduce the chance of an attacker successfully causing intentional collisions. (CVE-2011-4815)

It was found that Ruby did not reinitialize the PRNG (pseudorandom number generator) after forking a child process. This could eventually lead to the PRNG returning the same result twice. An attacker keeping track of the values returned by one child process could use this flaw to predict the values the PRNG would return in other child processes (as long as the parent process persisted). (CVE-2011-3009)

Red Hat would like to thank oCERT for reporting CVE-2011-4815. oCERT acknowledges Julian Walde and Alexander Klink as the original reporters of CVE-2011-4815.

All users of ruby are advised to upgrade to these updated packages, which contain backported patches to resolve these issues.


Update the affected packages.

See Also





Plugin Details

Severity: High

ID: 57747

File Name: redhat-RHSA-2012-0070.nasl

Version: $Revision: 1.12 $

Type: local

Agent: unix

Published: 2012/01/31

Modified: 2017/01/05

Dependencies: 12634

Risk Information

Risk Factor: High


Base Score: 7.8

Temporal Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Temporal Vector: CVSS2#E:F/RL:OF/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:irb, p-cpe:/a:redhat:enterprise_linux:ruby, p-cpe:/a:redhat:enterprise_linux:ruby-devel, p-cpe:/a:redhat:enterprise_linux:ruby-docs, p-cpe:/a:redhat:enterprise_linux:ruby-irb, p-cpe:/a:redhat:enterprise_linux:ruby-libs, p-cpe:/a:redhat:enterprise_linux:ruby-mode, p-cpe:/a:redhat:enterprise_linux:ruby-rdoc, p-cpe:/a:redhat:enterprise_linux:ruby-ri, p-cpe:/a:redhat:enterprise_linux:ruby-tcltk, cpe:/o:redhat:enterprise_linux:4, cpe:/o:redhat:enterprise_linux:5

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2012/01/30

Reference Information

CVE: CVE-2011-3009, CVE-2011-4815

BID: 49126, 51198

OSVDB: 74841, 78118

RHSA: 2012:0070